聲明:這裏的例子是項目剝離出來的,不完善,修訂版(以及源碼demo)傳送門:javascript
springMVC結合Jcrop實現頭像上傳裁剪預覽功能--javaweb修訂版css
先說明下我搭建的環境是:springMVC+spring+mybatis ,因爲表達能力欠缺。下面直接上代碼:html
1、jsp頁面:java
<form name="form" action="<%=request.getContextPath()%>/UploadDemo/uploadHeadImage" class="form-horizontal" method="post" enctype="multipart/form-data"> <div class="modal-body text-center"> <div class="zxx_main_con"> <div class="zxx_test_list"> <input class="photo-file" type="file" name="imgFile" id="fcupload" onchange="readURL(this);"/> <img alt="" src="" id="cutimg"/> <input type="hidden" id="x" name="x"/> <input type="hidden" id="y" name="y"/> <input type="hidden" id="w" name="w"/> <input type="hidden" id="h" name="h"/> </div> </div> </div> <div class="modal-footer"> <button id="submit" onclick="">上傳</button> </div> </form>
2、jcrop組件引用狀況:jquery
<link rel="stylesheet" href="<c:url value="/resources/uploadPlugin/css/jquery.Jcrop.css"/>" type="text/css"></link> <script type="text/javascript" src="<c:url value="/resources/uploadPlugin/scripts/jquery-1.8.3.js"/>"></script> <script type="text/javascript" src="<c:url value="/resources/uploadPlugin/scripts/jquery.Jcrop.js"/>"></script>
3、jcrop使用方法:(有兩種,先說我使用的,最後在介紹兩種方法的不一樣之處)web
<script type="text/javascript"> //定義一個全局api,這樣操做起來比較靈活 var api = null; function readURL(input) { if (input.files && input.files[0]) { var reader = new FileReader(); reader.readAsDataURL(input.files[0]); reader.onload = function (e) { $('#cutimg').removeAttr('src'); $('#cutimg').attr('src', e.target.result); api = $.Jcrop('#cutimg', { setSelect: [ 20, 20, 200, 200 ], aspectRatio: 1, onSelect: updateCoords }); }; if (api != undefined) { api.destroy(); } } function updateCoords(obj) { $("#x").val(obj.x); $("#y").val(obj.y); $("#w").val(obj.w); $("#h").val(obj.h); }; } </script>
4、後臺代碼:spring
@RequestMapping(value = "/uploadHeadImage") public String uploadHeadImage( HttpServletRequest request, @RequestParam(value = "x") String x, @RequestParam(value = "y") String y, @RequestParam(value = "h") String h, @RequestParam(value = "w") String w, @RequestParam(value = "imgFile") MultipartFile imageFile ) throws Exception{ System.out.println("==========Start============="); String realPath = request.getSession().getServletContext().getRealPath("/"); String resourcePath = "resources/uploadImages/"; if(imageFile!=null){ if(FileUploadUtil.allowUpload(imageFile.getContentType())){ String fileName = FileUploadUtil.rename(imageFile.getOriginalFilename()); int end = fileName.lastIndexOf("."); String saveName = fileName.substring(0,end); File dir = new File(realPath + resourcePath); if(!dir.exists()){ dir.mkdirs(); } File file = new File(dir,saveName+"_src.jpg"); imageFile.transferTo(file); String srcImagePath = realPath + resourcePath + saveName; int imageX = Integer.parseInt(x); int imageY = Integer.parseInt(y); int imageH = Integer.parseInt(h); int imageW = Integer.parseInt(w); //這裏開始截取操做 System.out.println("==========imageCutStart============="); ImageCut.imgCut(srcImagePath,imageX,imageY,imageW,imageH); System.out.println("==========imageCutEnd============="); } } return "user/uploadImg/test"; }
5、ImageCut.java工具類:api
/** * 截取圖片 * @param srcImageFile 原圖片地址 * @param x 截取時的x座標 * @param y 截取時的y座標 * @param desWidth 截取的寬度 * @param desHeight 截取的高度 */ public static void imgCut(String srcImageFile, int x, int y, int desWidth, int desHeight) { try { Image img; ImageFilter cropFilter; BufferedImage bi = ImageIO.read(new File(srcImageFile+"_src.jpg")); int srcWidth = bi.getWidth(); int srcHeight = bi.getHeight(); if (srcWidth >= desWidth && srcHeight >= desHeight) { Image image = bi.getScaledInstance(srcWidth, srcHeight,Image.SCALE_DEFAULT); cropFilter = new CropImageFilter(x, y, desWidth, desHeight); img = Toolkit.getDefaultToolkit().createImage( new FilteredImageSource(image.getSource(), cropFilter)); BufferedImage tag = new BufferedImage(desWidth, desHeight, BufferedImage.TYPE_INT_RGB); Graphics g = tag.getGraphics(); g.drawImage(img, 0, 0, null); g.dispose(); //輸出文件 ImageIO.write(tag, "JPEG", new File(srcImageFile+"_cut.jpg")); } } catch (Exception e) { e.printStackTrace(); } }
6、jcrop的兩種使用方式:mybatis
一、jQuery('#cropbox').Jcrop({
onChange: showCoords,
onSelect: showCoords
});app
二、var api = $.Jcrop('#cropbox',{
onChange: showPreview,
onSelect: showPreview,
aspectRatio: 1
});
這裏推薦你們使用第二種方式,將Jcrop生成的對象賦給一個全局變量,這樣操做起來更靈活,如調用api.destroy();方法能夠銷燬 Jcorp,這樣咱們在實際使用中會更靈活一些,由於直接改變要裁剪圖片的路徑會致使Jcorp的出錯,若是想要變動編輯的圖片咱們須要銷燬Jcorp, 變動圖片的屬性後再次爲圖片附加Jcorp。
參看:一、 jQuery Jcrop 圖像裁剪 二、Jcrop的官網